Room: Exhibit Hall | Forum 6
Purpose: Deep Inspiration Breath-Hold (DIBH) reduces cardiac dose in left-sided breast radiotherapy by 50%. Visual feedback increases DIBH reproducibility and stability. Recent studies found that tracking a marker block as a surrogate for the chest position is not always sufficient. Breathe Well (BW) is a novel couch-mounted device for visual DIBH guidance based on centre-of-chest (in-field) surface imaging. The randomised trial BRAVEHeart (Breast Radiotherapy Audio Visual Enhancement for sparing the Heart) is the first to compare DIBH accuracy using BW to the Respiratory Position Monitoring (RPM) system using an out-of-field marker block.
Methods: 40 patients are recruited and randomised (1:1) either into the BW or RPM arm. Treatment simulation is performed either with BW or RPM visual feedback according to the group allocation. For each system the DIBH tolerance zone is set to 5mm. While the allocated system is actively guiding the patient breathing, the other system is set up as well and recording the chest motion during simulation and treatment. The chest wall â€œground truthâ€? motion is extracted from EPID cine images collected for all treatment fields using chest/lung (primary) and chest/air (secondary) edge segmentation for evaluation of the breath hold accuracy. The primary hypothesis is that the accuracy of BW in maintaining the DIBH position is superior to the RPM system. Setup times of BW and RPM + screen for physical setup on the couch are measured.
Results: The first patient in the BRAVEHeart trial was randomised into the RPM arm and has completed treatment successfully. The breath hold accuracy measured in the EPID images was -0.3Â±0.3mm (motion in posterior direction). The setup times of BW and RPM were 18.1Â±7.9s and 22.1Â±13.7s, respectively.
Conclusion: We have defined a framework to investigate the efficacy of BW for DIBH guidance for the first time in a randomised trial.
Funding Support, Disclosures, and Conflict of Interest: Authors Steiner, Makhija and Keall are inventors on a patent filed for the Breathe Well technology. Paul Keall is a founder, shareholder and director of Opus Medical Pty Ltd, a company advancing the Breathe Well audiovisual biofeedback device. Kuldeep Makhija is a founder and shareholder of Opus Medical Pty Ltd.